Re: [PATCH 2/2] ls-files: add --sparse option

> Derrick Stolee <stolee@gmail.com> writes:
> 
>> You're talking about this hunk, right?
>>
>> if test -z "$GIT_TEST_CMP"
>> then
>> 	if test -n "$GIT_TEST_CMP_USE_COPIED_CONTEXT"
>> 	then
>> 		GIT_TEST_CMP="$DIFF -c"
>> 	else
>> 		GIT_TEST_CMP="$DIFF -u"
>> 	fi
>> fi
>>
>> This only switches from "diff -u" to "diff -c" if the
>> GIT_TEST_CMP_USE_COPIED_CONTEXT variable is set, but it is not set
>> by default. Thus, we are using "diff -u" by default throughout.
> 
> That it can be set merely means that somebody needed to work around
> the lack of "-u" format in their implementation of "diff".  It came
> to POSIX only at the Issue 7 of the standard (cf. [*1*]).
> 
> Unconditional use of "diff -u" is a breaking change for them.